Determination of amplitude and duration magnitudes and site residuals from short-period seismographs in northern California

1991 ◽  
Author(s):  
Jerry P. Eaton
1992 ◽  
Vol 82 (2) ◽  
pp. 533-579 ◽  
Author(s):  
Jerry P. Eaton

Abstract Equations for determining amplitude magnitude (MX) and duration magnitude (MF) that employ all calibrated instruments in the USGS short-period telemetered seismic network in northern California (NCSN) were developed and tested against a set of 1276 earthquakes from 1986 to 1990 that were analyzed on the Caltech-USGS processing system (CUSP). The expressions for decay of amplitude and record duration in these equations are functions of distance alone. Sensitivity corrections for both MX and MF are simply the logarithms of the ratios of the magnification of the reference instrument to that of the instrument actually used. Component corrections were chosen so as to minimize the dependence of instrument site residuals on instrument component. MF site residuals were found to be closely linked to MX site residuals in a manner that suggests both depend primarily on site amplification. Both MX and MF site residuals vary systematically with bedrock lithology: older well-consolidated rocks produce negative residuals (smaller amplitudes and shorter durations) and younger unconsolidated rocks produce positive residuals (larger amplitudes and longer durations). Average station magnitude residuals are virtually independent of distance from the epicenter to at least 800 km; and MX-MF, averaged over 0.5 unit magnitude intervals, is less than 0.05 from M0.5 to M5.5. Comparison of MX and MBK (ML, UC Berkeley) for 293 events in both the CUSP data set and the Berkeley catalog shows that calculated MX s are marginally larger than the corresponding MBK s. MX-MBK averages about + 0.04. The characteristics of the standard Wood-Anderson seismograph employed to calculate MX are: free period 0.8 sec, damping constant 0.8, and static magnification 2080.


2021 ◽  
Vol 2 (1) ◽  
pp. 01-05
Author(s):  
YASSINE CHAHBOUB ◽  
SZAVAI Szabolcs

The Gurson – Tvergaard – Needleman (GTN) mechanical model is widely used to predict the failure of materials based on laboratory specimens, direct identification of Gurson – Tvergaard – Needleman parameters is not easy and time-consuming, and the most used method to determine them is the combination between the experimental results and those of the finite elements, the process consists of repeating the simulations several times until the simulation data matches the experimental data obtained at the specimen level.This article aims to find GTN parameters for the Compact Tension (CT) and Single Edge Tensile Test (SENT) specimen based on the Notch Specimen (NT) using the Artificial Neural Network (ANN) approach. . This work presents how the ANN could help us determine the parameters of GTN in a very short period of time. The results obtained show that ANN is an excellent tool for determining GTN parameters.


2013 ◽  
Vol 52 (3) ◽  
pp. 1634-1641 ◽  
Author(s):  
Pedro Cerezal Mezquita ◽  
Blanca E. Barragán Huerta ◽  
Jenifer C. Palma Ramírez ◽  
Claudia P. Ortíz Hinojosa

1973 ◽  
Vol 63 (2) ◽  
pp. 599-614 ◽  
Author(s):  
M. E. O'Neill ◽  
J. H. Healy

abstract A simple method of estimating source dimensions and stress drops of small earthquakes is presented. The basic measurement is the time from the first break to the first zero crossing on short-period seismograms. Graphs relating these measurements to rise time as a function of Q and instrument response permit an estimate of earthquake source parameters without the calculation of spectra. Tests on data from Rangely, Colorado, and Hollister, California, indicate that the method gives reasonable results.


2021 ◽  
Author(s):  
Jun Araki

Abstract The surface carboxyl and sulfate groups on cellulose nanowhiskers were quantified via the adsorption of toluidine blue O (TBO), a cationic dye. Here, simple and rapid protocols, such as mixing the nanowhisker suspensions with a dye solution, separating the supernatants via centrifugation, and determining the excess dye concentration via visible light absorbance techniques, were used to obtain reproducible results comparable with those obtained via titration. In addition to facilitating the discrete quantification of the sulfate and carboxyl groups, the TBO adsorption method enabled carboxyl quantification in the presence of mercapto groups, which was difficult to achieve via titration. The adsorption of TBO onto the carboxyl groups was completed within 30 min, enabling the rapid treatment of many samples within a short period.


2017 ◽  
Vol 11 (8) ◽  
pp. 1
Author(s):  
Jinan Abdil-Hasan

This study is dedicated for the determination of the distribution of thermal energy resulted from different types of a 50-70 KT yield nuclear explosion; surface, aerial, in different locations away from the explosion center and considering the differences in the transmittance factor and visibility conditions that may affect the distribution of thermal energy. The results showed that the majority of released thermal energy occurs during a very short period of time after explosion, and reaches its maximum of 22 KT after about 3.1 sec. Also, it was determined the absence of significant effect for the visibility degree on the value of the total thermal exposure for both types of explosions, and that the thermal exposure due to the surface explosion is about 60% of its value in case of the aerial explosion.


2014 ◽  
Vol 58 (4) ◽  
pp. 573-579 ◽  
Author(s):  
Anna Gajda ◽  
Andrzej Posyniak ◽  
Grzegorz Tomczyk

Abstract For the purpose of quantitative determination of doxycycline (DC) residues in tissues, a sensitive liquid chromatography - tandem mass spectrometry (LC-MS/MS) method was developed. The method was used to determine DC residues in chicken tissues (breast and thigh muscle, liver and kidney) after oral administration with drinking water to five-weak-old broiler chickens. The DC was administered for five consecutive days at a therapeutic dose of 10 mg/kg b.w. once a day. The tissues were collected after 6 h, 24 h, 7 d, and 8 d. The method was validated and the decision limit was established for muscle - 109.2 μg/kg, for liver - 326.1 μg/kg, and for kidney - 634.0 μg/kg. The detection limit was 2 μg/kg and the limit of quantification was 5 μg/kg. In a short period after ceasing the treatment, the detected concentrations of DC were much higher than the established maximum residue limit values. The highest residue concentrations of DC were observed in the kidney, followed by the liver and muscle. The lowest concentration of DC was determined in tight muscle.


2019 ◽  
Vol 40 (2) ◽  
Author(s):  
Juan Zhao ◽  
Haibo Lin ◽  
Jinhuo Liu ◽  
Yanben Han

Author(s):  
J. V. Jelley ◽  
E. B. Paul

Equipment has been designed and constructed for the interruption of the ion beam in a high-voltage accelerating tube and for the detection and measurement of the period of short-lived radioactive elements. This method has been applied to the measurement of the half-life of 12B which has been found to be 27 ± 2 msec. The reaction 15N(n, α)12B has been detected.


1976 ◽  
Vol 66 (5) ◽  
pp. 1459-1484
Author(s):  
Paul G. Somerville ◽  
Ralph A. Wiggins ◽  
Robert M. Ellis

abstract Source parameters of two shallow earthquakes have been determined by the time-domain analysis of short-period teleseismic recordings. For each event, the effect of the receiver crust was deconvolved from a set of globally distributed recordings using the homomorphic method. The resulting seismograms were compared with the form of the elastic-wave radiation computed from Savage's model of radially spreading rupture on a plane elliptical fault surface. This time-domain approach has permitted the determination of several kinematic parameters pertaining to the dynamics of rupture that are not ordinarily evaluated from spectral analysis. These parameters are rupture velocity, the direction of farthest rupture propagation, and the duration of a ramp dislocation time function which was prescribed to be the same everywhere on the fault surface. The application of a general linear inverse scheme has shown that the model parameters (notably rupture velocity and dimension) are only weakly coupled. Inversion is also used to determine the range of acceptable parameter values and indicates the importance of array recordings in constraining the models. A consistent discrepancy between the observed and model seismograms during the first half-cycle of motion is attributed to the incorrect prescription of the dislocation time function. It is suggested that a space-dependent function determined theoretically by Kostrov in 1964 would tend to remove this discrepancy.


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